الخلاصة:
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VSM Vibrating sample magnetometer
MRI Magnetic resonance imaging
FWHM Full width at half-maximum
PXRD Powder X-ray diffraction
GMR Giant magneto resistance
PLD Pulse Laser Depostion
MHA Mueller Hinton Agar
RFA Radio frequency ablation
MNPs Micronized nanoparticals
MR Magmatic Recording
MMONPs magnetic metal oxide nanoparticles
.
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ABSTRACT:
In this research, we prepared magnetic nano particles in format Co1-xNix Fe2 O4
in two methods. The first method is Co-precipitationnand were used pulsed laser
deposition (PLD).
We used a mixture of nickel nitrate, cobalt nitrate, iron nitrate, as well as sodium
hydroxide as a chelating agent to balance the ratio of the oxidizing agent.
The ferrite NPs were calcined at temperatures (300 °C) for 3 hr. to remove water
content and unwanted impurities and to obtain a better single-phase spinel
structure. The resulting powder is then compressed into a disc with a diameter of (2
cm) and then we use laser deposition technology to obtain thin film.
Structure and magnetic properties of the NPs were tested using XRD, FE-SEM,
FTIR, and finally the Vibrating Sample Magnetometer (VSM), which revealed the
presence of Super para magnetic samples. The x-ray spectrum shows that the pattern
of the particles formed is of the face -centered cubic and the theoretical values of the
lattice constant and crystalline size (D) were calculated .The crystalline size
calculated was located in the range (22.6-26.6 nm), either in the pulsed laser
deposition method in the range (13.7)nm, which reflects the highly crystalline nature
of these nanoparticles. The FTIR spectrum shows two absorption bands ranging
between 400 and 600 cm-1. These bands indicated that the composition of the
spectrum for all the samples is ferrite.
The Field emission scanning electron microscopes (FE-SEM) images
confirmed that the preparation methods produced spherical nanoparticles with a
slight change in the particle size distribution. The average particle size by coprecipitation
had estimated to be about 23 nm and the average particle size by
pulsed laser deposition(PLD) method had estimated to be about 20 nm.
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The magnetic properties vibrating sample magnetometer (VSM) showed
good correlation with the structural parameters of the spinal structure, which
increased with the Ni content.
When using nanoparticles prepared by co-precipitation method on
Escherichia coli and Streptococcus bacteria, the highest inhibition zone ranged
from (27-33) mm. When using nanoparticles prepared by using the method of
pulsd laser deposition on the same types of bacteria, (S.aureus)was found to have
the highest inhibition zone (22-32) mm , while Bacteria(Escherichia coli) the
inhibition zone ( 27-30) mm.
